Supragingival Plaque Microbiota Dysbiosis In Sjögren’S Syndrome

Primary Sjögren's syndrome (pSS) patients frequently exhibit oral microbial dysbiosis and Candida colonization, yet the supragingival plaque microbiota characteristics in this population remain underexplored. This study aimed to analyze the supragingival dental plaque microbiome among Candida-carriage pSS patients using high-throughput sequencing. We enrolled 15 age- and gender-matched female participants divided into three groups: Candida- carriage pSS [decayed, missing, and filled teeth (DMFT) score=22±6.7; n=5], oral candidiasis patients (DMFT=17±6.5; n=5), and caries-active healthy controls (DMFT=14±3.8; n=5). Supragingival plaque samples were collected from non-carious surfaces, followed by 16S rRNA gene (V3-V4 region) amplification and Illumina HiSeq 2500 sequencing. Taxonomic profiling was performed using SILVA database alignment via Mothur v1.40.0, with α/β-diversity analyses. We detect 464, 307 and 199 operational taxonomic units (OTUs) of pSS patients, oral candidiasis patients and healthy patients respectively. Treponema (9.4%/9.7%/10%), Lactobacillus (10%/9.8%/7.5%), Streptococcus (9.2%/7.5%/7.3%), Selenomonas (7.8%/7.1%/8.5%), and Veillonella (7.8%/7%/7.7%) were the primary genera in the three groups. Microbial diversity (alpha diversity and beta diversity) was significantly decreased in pSS patients. Our findings reveal a unique supragingival plaque microbiota signature in pSS patients characterized by reduced diversity and aciduric bacterial enrichment, independent of Candida carriage status and DMFT scores. These results suggest plaque microbiota as a potential diagnostic biomarker for pSS.